Geology of the South- West of England, 135 



3^0a?ICES OIF nyCEIMIOII^S 



GEOLOGY OF THE SOUTH-WEST OF ENGLAND. 



1. — ''On the Middle and Upper Lias of the South-west of 



England." By Charles Moore, F.G.S. 



Reprinted from the Proceedings of the Somersetshire Archaeological and Natural 

 History Society. Vol. xiii. 1865-66. 



2. — " On Abnormal Conditions of Secondary Deposits when con- 

 nected with the Somersetshire and South Wales Coal- 

 Basin; AND ON THE AgE OF THE SuTTON AND SOUTHERNDOWN 



Series." By Charles Moore, F.G.S. 



Quarterly Journal of the Geological Society, December 1, 1867. Supplementary No. 



IN the first of these papers, Mr. Moore describes the beds between 

 the so-called Upper Lias Sands and the zone of Ammonites rari- 

 costatus, the highest member of the Lower Lias, in their passage 

 through Somersetshire into Gloucestershire. He gives numerous 

 sections, and lists of fossils, with descriptions and illustrations of 

 the Mollusca, — some of which are new species. A typical section at 

 Ilminster, showing 158 feet of Middle Lias, and 10 feet of Upper 

 Lias, is first explained, and then compared with other sections in the 

 South-west of England. The beds of the Middle Lias consist of 

 irregular thickly-bedded marlstones, marls, and sands, with much 

 ironstone. The Upper Lias comprises thin beds of clay and lime- 

 stone, crowded with organic remains. Though iron is plentifully 

 distributed in the Middle Lias of the district under consideration, 

 the beds are not quite thick enough to be worked with profit. 



In noticing the Ichthyosauri of the Upper Lias, Mr. Moore re- 

 marks that whilst these reptiles appear in Liassic times to have fed 

 on the naked cephalopoda, others of this family in their turn retali- 

 ated. In several instances their bodies have been found covered by 

 colonies of Ammonites, which were evidently preying upon the 

 Ichthyosauri before they were finally entombed. 



Mr. Moore discusses the recent classification with the Upper Lias, 

 of the Yellow Sands beneath the Inferior Oolite, and states that he 

 has never been able to recognize this arrangement. Not only is 

 there in each horizon as distinct a fauna in its general facie s as 

 can be found in any other formation, but wherever the junction 

 of the sands with the Upper Lias is observed, there is a most marked 

 and permanent lithological distinction in argillaceous beds crowded 

 with Ammonites, etc., capped by yellow sands, with but few 

 evidences in their lower beds of organic life. Moreover, he adds, 

 that wherever the junction of the Upper Lias with the Sands is ex- 

 posed, the former presents an eroded surface. 



Mr. H. B. Brady contributes a synopsis of the Foraminifera ; and 

 Mr. Henry Woodward furnishes a communication on the Crustacea, 

 wherein he points out the interesting fact that many forms, common 

 to the Lias, agree in identity with species found only in the Litho- 

 graphic stone of Solenhofen, showing that they must have migrated 



